/***
 * ASM: a very small and fast Java bytecode manipulation framework
 * Copyright (c) 2000-2007 INRIA, France Telecom
 * All rights reserved.
 */
package org.rsbot.loader.asm;

/**
 * A visitor to visit a Java method. The methods of this interface must be
 * called in the following order: [ <tt>visitAnnotationDefault</tt> ] (
 * <tt>visitAnnotation</tt> | <tt>visitParameterAnnotation</tt> |
 * <tt>visitAttribute</tt> )* [ <tt>visitCode</tt> ( <tt>visitFrame</tt> |
 * <tt>visit</tt><i>X</i>Insn</tt> | <tt>visitLabel</tt> | <tt>visitTryCatchBlock</tt> |
 * <tt>visitLocalVariable</tt> | <tt>visitLineNumber</tt>)* <tt>visitMaxs</tt> ]
 * <tt>visitEnd</tt>. In addition, the <tt>visit</tt><i>X</i>Insn</tt>
 * and <tt>visitLabel</tt> methods must be called in the sequential order of
 * the bytecode instructions of the visited code, <tt>visitTryCatchBlock</tt>
 * must be called <i>before</i> the labels passed as arguments have been
 * visited, and the <tt>visitLocalVariable</tt> and <tt>visitLineNumber</tt>
 * methods must be called <i>after</i> the labels passed as arguments have been
 * visited.
 *
 * @author Eric Bruneton
 */
public interface MethodVisitor {

	// -------------------------------------------------------------------------
	// Annotations and non standard attributes
	// -------------------------------------------------------------------------

	/**
	 * Visits the default value of this annotation interface method.
	 *
	 * @return a visitor to the visit the actual default value of this
	 *         annotation interface method, or <tt>null</tt> if this visitor
	 *         is not interested in visiting this default value. The 'name'
	 *         parameters passed to the methods of this annotation visitor are
	 *         ignored. Moreover, exacly one visit method must be called on this
	 *         annotation visitor, followed by visitEnd.
	 */
	AnnotationVisitor visitAnnotationDefault();

	/**
	 * Visits an annotation of this method.
	 *
	 * @param desc    the class descriptor of the annotation class.
	 * @param visible <tt>true</tt> if the annotation is visible at runtime.
	 * @return a visitor to visit the annotation values, or <tt>null</tt> if
	 *         this visitor is not interested in visiting this annotation.
	 */
	AnnotationVisitor visitAnnotation(String desc, boolean visible);

	/**
	 * Visits an annotation of a parameter this method.
	 *
	 * @param parameter the parameter index.
	 * @param desc      the class descriptor of the annotation class.
	 * @param visible   <tt>true</tt> if the annotation is visible at runtime.
	 * @return a visitor to visit the annotation values, or <tt>null</tt> if
	 *         this visitor is not interested in visiting this annotation.
	 */
	AnnotationVisitor visitParameterAnnotation(
			int parameter,
			String desc,
			boolean visible);

	/**
	 * Visits a non standard attribute of this method.
	 *
	 * @param attr an attribute.
	 */
	void visitAttribute(Attribute attr);

	/**
	 * Starts the visit of the method's code, if any (i.e. non abstract method).
	 */
	void visitCode();

	/**
	 * Visits the current state of the local variables and operand stack
	 * elements. This method must(*) be called <i>just before</i> any
	 * instruction <b>i</b> that follows an unconditional branch instruction
	 * such as GOTO or THROW, that is the target of a jump instruction, or that
	 * starts an exception handler block. The visited types must describe the
	 * values of the local variables and of the operand stack elements <i>just
	 * before</i> <b>i</b> is executed. <br> <br> (*) this is mandatory only
	 * for classes whose version is greater than or equal to
	 * {@link Opcodes#V1_6 V1_6}. <br> <br> Packed frames are basically
	 * "deltas" from the state of the previous frame (very first frame is
	 * implicitly defined by the method's parameters and access flags): <ul>
	 * <li>{@link Opcodes#F_SAME} representing frame with exactly the same
	 * locals as the previous frame and with the empty stack.</li> <li>{@link Opcodes#F_SAME1}
	 * representing frame with exactly the same locals as the previous frame and
	 * with single value on the stack (<code>nStack</code> is 1 and
	 * <code>stack[0]</code> contains value for the type of the stack item).</li>
	 * <li>{@link Opcodes#F_APPEND} representing frame with current locals are
	 * the same as the locals in the previous frame, except that additional
	 * locals are defined (<code>nLocal</code> is 1, 2 or 3 and
	 * <code>local</code> elements contains values representing added types).</li>
	 * <li>{@link Opcodes#F_CHOP} representing frame with current locals are
	 * the same as the locals in the previous frame, except that the last 1-3
	 * locals are absent and with the empty stack (<code>nLocals</code> is 1,
	 * 2 or 3). </li> <li>{@link Opcodes#F_FULL} representing complete frame
	 * data.</li> </li> </ul>
	 *
	 * @param type   the type of this stack map frame. Must be
	 *               {@link Opcodes#F_NEW} for expanded frames, or
	 *               {@link Opcodes#F_FULL}, {@link Opcodes#F_APPEND},
	 *               {@link Opcodes#F_CHOP}, {@link Opcodes#F_SAME} or
	 *               {@link Opcodes#F_APPEND}, {@link Opcodes#F_SAME1} for compressed
	 *               frames.
	 * @param nLocal the number of local variables in the visited frame.
	 * @param local  the local variable types in this frame. This array must not
	 *               be modified. Primitive types are represented by
	 *               {@link Opcodes#TOP}, {@link Opcodes#INTEGER},
	 *               {@link Opcodes#FLOAT}, {@link Opcodes#LONG},
	 *               {@link Opcodes#DOUBLE},{@link Opcodes#NULL} or
	 *               {@link Opcodes#UNINITIALIZED_THIS} (long and double are
	 *               represented by a single element). Reference types are represented
	 *               by String objects (representing internal names), and uninitialized
	 *               types by Label objects (this label designates the NEW instruction
	 *               that created this uninitialized value).
	 * @param nStack the number of operand stack elements in the visited frame.
	 * @param stack  the operand stack types in this frame. This array must not
	 *               be modified. Its content has the same format as the "local" array.
	 * @throw IllegalStateException if a frame is visited just after another
	 * one, without any instruction between the two (unless this frame
	 * is a Opcodes#F_SAME frame, in which case it is silently ignored).
	 */
	void visitFrame(
			int type,
			int nLocal,
			Object[] local,
			int nStack,
			Object[] stack);

	// -------------------------------------------------------------------------
	// Normal instructions
	// -------------------------------------------------------------------------

	/**
	 * Visits a zero operand instruction.
	 *
	 * @param opcode the opcode of the instruction to be visited. This opcode is
	 *               either NOP, ACONST_NULL, ICONST_M1, ICONST_0, ICONST_1, ICONST_2,
	 *               ICONST_3, ICONST_4, ICONST_5, LCONST_0, LCONST_1, FCONST_0,
	 *               FCONST_1, FCONST_2, DCONST_0, DCONST_1, IALOAD, LALOAD, FALOAD,
	 *               DALOAD, AALOAD, BALOAD, CALOAD, SALOAD, IASTORE, LASTORE, FASTORE,
	 *               DASTORE, AASTORE, BASTORE, CASTORE, SASTORE, POP, POP2, DUP,
	 *               DUP_X1, DUP_X2, DUP2, DUP2_X1, DUP2_X2, SWAP, IADD, LADD, FADD,
	 *               DADD, ISUB, LSUB, FSUB, DSUB, IMUL, LMUL, FMUL, DMUL, IDIV, LDIV,
	 *               FDIV, DDIV, IREM, LREM, FREM, DREM, INEG, LNEG, FNEG, DNEG, ISHL,
	 *               LSHL, ISHR, LSHR, IUSHR, LUSHR, IAND, LAND, IOR, LOR, IXOR, LXOR,
	 *               I2L, I2F, I2D, L2I, L2F, L2D, F2I, F2L, F2D, D2I, D2L, D2F, I2B,
	 *               I2C, I2S, LCMP, FCMPL, FCMPG, DCMPL, DCMPG, IRETURN, LRETURN,
	 *               FRETURN, DRETURN, ARETURN, RETURN, ARRAYLENGTH, ATHROW,
	 *               MONITORENTER, or MONITOREXIT.
	 */
	void visitInsn(int opcode);

	/**
	 * Visits an instruction with a single int operand.
	 *
	 * @param opcode  the opcode of the instruction to be visited. This opcode is
	 *                either BIPUSH, SIPUSH or NEWARRAY.
	 * @param operand the operand of the instruction to be visited.<br> When
	 *                opcode is BIPUSH, operand value should be between Byte.MIN_VALUE
	 *                and Byte.MAX_VALUE.<br> When opcode is SIPUSH, operand value
	 *                should be between Short.MIN_VALUE and Short.MAX_VALUE.<br> When
	 *                opcode is NEWARRAY, operand value should be one of
	 *                {@link Opcodes#T_BOOLEAN}, {@link Opcodes#T_CHAR},
	 *                {@link Opcodes#T_FLOAT}, {@link Opcodes#T_DOUBLE},
	 *                {@link Opcodes#T_BYTE}, {@link Opcodes#T_SHORT},
	 *                {@link Opcodes#T_INT} or {@link Opcodes#T_LONG}.
	 */
	void visitIntInsn(int opcode, int operand);

	/**
	 * Visits a local variable instruction. A local variable instruction is an
	 * instruction that loads or stores the value of a local variable.
	 *
	 * @param opcode the opcode of the local variable instruction to be visited.
	 *               This opcode is either ILOAD, LLOAD, FLOAD, DLOAD, ALOAD, ISTORE,
	 *               LSTORE, FSTORE, DSTORE, ASTORE or RET.
	 * @param var    the operand of the instruction to be visited. This operand is
	 *               the index of a local variable.
	 */
	void visitVarInsn(int opcode, int var);

	/**
	 * Visits a type instruction. A type instruction is an instruction that
	 * takes the internal name of a class as parameter.
	 *
	 * @param opcode the opcode of the type instruction to be visited. This
	 *               opcode is either NEW, ANEWARRAY, CHECKCAST or INSTANCEOF.
	 * @param type   the operand of the instruction to be visited. This operand
	 *               must be the internal name of an object or array class (see {@link
	 *               Type#getInternalName() getInternalName}).
	 */
	void visitTypeInsn(int opcode, String type);

	/**
	 * Visits a field instruction. A field instruction is an instruction that
	 * loads or stores the value of a field of an object.
	 *
	 * @param opcode the opcode of the type instruction to be visited. This
	 *               opcode is either GETSTATIC, PUTSTATIC, GETFIELD or PUTFIELD.
	 * @param owner  the internal name of the field's owner class (see {@link
	 *               Type#getInternalName() getInternalName}).
	 * @param name   the field's name.
	 * @param desc   the field's descriptor (see {@link Type Type}).
	 */
	void visitFieldInsn(int opcode, String owner, String name, String desc);

	/**
	 * Visits a method instruction. A method instruction is an instruction that
	 * invokes a method.
	 *
	 * @param opcode the opcode of the type instruction to be visited. This
	 *               opcode is either INVOKEVIRTUAL, INVOKESPECIAL, INVOKESTATIC,
	 *               INVOKEINTERFACE or INVOKEDYNAMIC.
	 * @param owner  the internal name of the method's owner class (see {@link
	 *               Type#getInternalName() getInternalName})
	 *               or {@link org.rsbot.loader.asm.Opcodes#INVOKEDYNAMIC_OWNER}.
	 * @param name   the method's name.
	 * @param desc   the method's descriptor (see {@link Type Type}).
	 */
	void visitMethodInsn(int opcode, String owner, String name, String desc);

	/**
	 * Visits a jump instruction. A jump instruction is an instruction that may
	 * jump to another instruction.
	 *
	 * @param opcode the opcode of the type instruction to be visited. This
	 *               opcode is either IFEQ, IFNE, IFLT, IFGE, IFGT, IFLE, IF_ICMPEQ,
	 *               IF_ICMPNE, IF_ICMPLT, IF_ICMPGE, IF_ICMPGT, IF_ICMPLE, IF_ACMPEQ,
	 *               IF_ACMPNE, GOTO, JSR, IFNULL or IFNONNULL.
	 * @param label  the operand of the instruction to be visited. This operand
	 *               is a label that designates the instruction to which the jump
	 *               instruction may jump.
	 */
	void visitJumpInsn(int opcode, Label label);

	/**
	 * Visits a label. A label designates the instruction that will be visited
	 * just after it.
	 *
	 * @param label a {@link Label Label} object.
	 */
	void visitLabel(Label label);

	// -------------------------------------------------------------------------
	// Special instructions
	// -------------------------------------------------------------------------

	/**
	 * Visits a LDC instruction.
	 *
	 * @param cst the constant to be loaded on the stack. This parameter must be
	 *            a non null {@link Integer}, a {@link Float}, a {@link Long}, a
	 *            {@link Double} a {@link String} (or a {@link Type} for
	 *            <tt>.class</tt> constants, for classes whose version is 49.0 or
	 *            more).
	 */
	void visitLdcInsn(Object cst);

	/**
	 * Visits an IINC instruction.
	 *
	 * @param var       index of the local variable to be incremented.
	 * @param increment amount to increment the local variable by.
	 */
	void visitIincInsn(int var, int increment);

	/**
	 * Visits a TABLESWITCH instruction.
	 *
	 * @param min    the minimum key value.
	 * @param max    the maximum key value.
	 * @param dflt   beginning of the default handler block.
	 * @param labels beginnings of the handler blocks. <tt>labels[i]</tt> is
	 *               the beginning of the handler block for the <tt>min + i</tt> key.
	 */
	void visitTableSwitchInsn(int min, int max, Label dflt, Label[] labels);

	/**
	 * Visits a LOOKUPSWITCH instruction.
	 *
	 * @param dflt   beginning of the default handler block.
	 * @param keys   the values of the keys.
	 * @param labels beginnings of the handler blocks. <tt>labels[i]</tt> is
	 *               the beginning of the handler block for the <tt>keys[i]</tt> key.
	 */
	void visitLookupSwitchInsn(Label dflt, int[] keys, Label[] labels);

	/**
	 * Visits a MULTIANEWARRAY instruction.
	 *
	 * @param desc an array type descriptor (see {@link Type Type}).
	 * @param dims number of dimensions of the array to allocate.
	 */
	void visitMultiANewArrayInsn(String desc, int dims);

	// -------------------------------------------------------------------------
	// Exceptions table entries, debug information, max stack and max locals
	// -------------------------------------------------------------------------

	/**
	 * Visits a try catch block.
	 *
	 * @param start   beginning of the exception handler's scope (inclusive).
	 * @param end     end of the exception handler's scope (exclusive).
	 * @param handler beginning of the exception handler's code.
	 * @param type    internal name of the type of exceptions handled by the
	 *                handler, or <tt>null</tt> to catch any exceptions (for "finally"
	 *                blocks).
	 * @throws IllegalArgumentException if one of the labels has already been
	 *                                  visited by this visitor (by the {@link #visitLabel visitLabel}
	 *                                  method).
	 */
	void visitTryCatchBlock(Label start, Label end, Label handler, String type);

	/**
	 * Visits a local variable declaration.
	 *
	 * @param name      the name of a local variable.
	 * @param desc      the type descriptor of this local variable.
	 * @param signature the type signature of this local variable. May be
	 *                  <tt>null</tt> if the local variable type does not use generic
	 *                  types.
	 * @param start     the first instruction corresponding to the scope of this
	 *                  local variable (inclusive).
	 * @param end       the last instruction corresponding to the scope of this local
	 *                  variable (exclusive).
	 * @param index     the local variable's index.
	 * @throws IllegalArgumentException if one of the labels has not already
	 *                                  been visited by this visitor (by the
	 *                                  {@link #visitLabel visitLabel} method).
	 */
	void visitLocalVariable(
			String name,
			String desc,
			String signature,
			Label start,
			Label end,
			int index);

	/**
	 * Visits a line number declaration.
	 *
	 * @param line  a line number. This number refers to the source file from
	 *              which the class was compiled.
	 * @param start the first instruction corresponding to this line number.
	 * @throws IllegalArgumentException if <tt>start</tt> has not already been
	 *                                  visited by this visitor (by the {@link #visitLabel visitLabel}
	 *                                  method).
	 */
	void visitLineNumber(int line, Label start);

	/**
	 * Visits the maximum stack size and the maximum number of local variables
	 * of the method.
	 *
	 * @param maxStack  maximum stack size of the method.
	 * @param maxLocals maximum number of local variables for the method.
	 */
	void visitMaxs(int maxStack, int maxLocals);

	/**
	 * Visits the end of the method. This method, which is the last one to be
	 * called, is used to inform the visitor that all the annotations and
	 * attributes of the method have been visited.
	 */
	void visitEnd();
}
